This invention relates generally as indicated to a fluid actuator, and, more particularly, to a fluid actuator including a composite piston rod which incorporates methods of attachment of one or more non-integral piston heads in order to efficiently utilize the directional composite material, and to simplify fabrication.
In copending U.S. patent applications Ser. Nos. 642,539, now U.S. Pat. No. 4,697,499, dated Oct. 6, 1987, and 642,540, both filed Aug. 20, 1984, such latter application having been abandonded in favor of a continuation application Ser. No. 834,501, filed Feb. 28, 1986, now U.S. Pat. No. 4,685,384, dated Aug. 11, 1987, and assigned to the same assignee as the present application, there are shown several different fluid actuator designs intended for use in flight controls of aircraft and other high pressure applications in which the cylinder walls are made of relatively high strength to weight composite materials in order to obtain a substantial reduction in the weight of the cylinders without sacrificing strength.
By the same token, it would be desirable to make the piston rod out of similar type composite materials so that the weight of the rod, like that of the cylinder, could also be substantially reduced. Moreover, it would be desirable to provide for the attachment of one or more non-integral piston heads to the composite rod structure in order to efficiently utilize the directional composite material, and to simplify fabrication. Also, it would be desirable to provide such a composite piston rod with the requisite sealing and rod end attachments along with increased fatigue resistance, damage tolerance, and ballistic tolerance.